17-11-2019, 08:52 PM
(This post was last modified: 17-11-2019, 08:56 PM by Mike Watterson.)
I'll look out the schematics and export images from Eagle. I've no idea if the current free version of Eagle (if there is one with the current owner) can read my ancient schematics.
I used the TDA7330 with a 4.332MHz crystal. No, it's not the PAL subcarrier frequency.
Managed to get to work on a TDA7088 clone as well as real radio. I also added a TDA7040 stereo decoder. I use little DIL headers for the SMT ICs. The TDA7088 needs it's 70KHz IF filter components adjusted a little for RDS and Stereo. Both worked better on the "data" connector of the Yaesu FT817ND. I found it had FM de-emphasis TWICE. I remove the 1st cap that was on the FM detector. The rig uses a regular FM Radio part for WBFM Band II but a different IF and detector for FM on all other bands. The "data" connector has unfiltered audio.
Just about any midrange PIC18F will do. Depends on what else you want. The 18F4550 is easy to have a USB slave (just add connector, a capacitor and SW for HID, Serial or Mass Storage emulation). I mostly used JAL, but some Assembler. Can be used inline too. Software serial data reading used for the TDA7330 1170 bps. Much easier on a PIC in JAL or Assembler or C than on Windows/Linux/Mac OS.
Version 2
Not shown is the PIC and its display.
I don't recommend the TDA7088 or clone for Stereo and/or RDS, but it can work.
I've added the TDA7040 SM IC to some valve tuners that had a now unavailable MPX option. Powered off the 6.3AC via a rectifier and regulator. A pot added at the input to set level. Doesn't take long to make up on stripboard and the DIL adaptor. Regular size iron and reflow the solder.
I'll email a pack to Murphy310 later in the week.
I got some standalone PIC (add your own resistors and stripboard) from "PIRA" to implement TTL Serial to 57kHz RDS encoding.
I used the TDA7330 with a 4.332MHz crystal. No, it's not the PAL subcarrier frequency.
Managed to get to work on a TDA7088 clone as well as real radio. I also added a TDA7040 stereo decoder. I use little DIL headers for the SMT ICs. The TDA7088 needs it's 70KHz IF filter components adjusted a little for RDS and Stereo. Both worked better on the "data" connector of the Yaesu FT817ND. I found it had FM de-emphasis TWICE. I remove the 1st cap that was on the FM detector. The rig uses a regular FM Radio part for WBFM Band II but a different IF and detector for FM on all other bands. The "data" connector has unfiltered audio.
Just about any midrange PIC18F will do. Depends on what else you want. The 18F4550 is easy to have a USB slave (just add connector, a capacitor and SW for HID, Serial or Mass Storage emulation). I mostly used JAL, but some Assembler. Can be used inline too. Software serial data reading used for the TDA7330 1170 bps. Much easier on a PIC in JAL or Assembler or C than on Windows/Linux/Mac OS.
Version 2
Not shown is the PIC and its display.
I don't recommend the TDA7088 or clone for Stereo and/or RDS, but it can work.
I've added the TDA7040 SM IC to some valve tuners that had a now unavailable MPX option. Powered off the 6.3AC via a rectifier and regulator. A pot added at the input to set level. Doesn't take long to make up on stripboard and the DIL adaptor. Regular size iron and reflow the solder.
I'll email a pack to Murphy310 later in the week.
I got some standalone PIC (add your own resistors and stripboard) from "PIRA" to implement TTL Serial to 57kHz RDS encoding.
